Elevator.



PATENTED DEC. 3, 1907.

J. W. BROWN. ELEVATOR.

APPLIUATION FILED rmms. 1907.

INVEN TORI WITNESSES TH: NORRIS P5152: co, WASHHIGYON, z:v c.

JOHN WALTER BROWN, OF EAST SHEEN, ENGLAND.

ELEVATOR.

Specification of Letters Patent.

Patented Dec. 3, 1907.

Original application filed February 61 1904 Serial No. 192.430. Divided and this application filed February 18. 1907.

Serial No. 358079.

T 0 all whom it may concern:

Be it known that I, JOHN VVALTER BROWN, a subject of the King of Great Britain and Ireland, residing at 92 East Sheen avenue, East Sheen, in the county of Surrey, England, civil engineer, have invented new and useful Improvements in Elevators, of which the following is a specification.

In working lifts or elevators, it is common to employ hydraulic motors or electric motors. The former possess great advantages in respect to safety, ease of control and low cost of maintenance; while the latter are remarkable for their economy in cost of working.

The object of my invention is to combine the advantages of both systemsi The accompanying drawing illustrates the application of this invention (a division of my application for Letters Patent filed 6th Eeby. 1904, Ser. No. 192430) to a hoisting cylinder E of the ram type, with two or more rams and cylinders. For the balance cylinder, I substitute a set of hydraulic pumps E driven by electric motors J, and between the controlling-valve and the pumps I provide a by-pass valve M, which may be combined with the controlling valve G, or may be connected to the hand-rope a or other apparatus for working the controlling-valve. The hoisting cylinder E is provided with a ram, or rams c 6 for lifting, and a ram, or rams 6 for lowering the cage; the raising and lowering rams being so proportioned as to be of equal displacement. The ram 6 is connected to a sheave B around which. the hoist-rope passes, and is thence led to the lift A by way of guide-pulleys B B. The counterweight F which is equal to the cage and half the load, or thereabout, is attached to the cross head 6 or to prolongations of the rams 6 6 The cylinders of the lifting and lowering rams are in communication with the valve chamber 9 of the controlling valve G by means of pipes g g each having two branches leading to the valve-chamber. The delivery pipe 9 and the suction pipe 9 of the pump E are also in communication with the valvechamber 9.

The action is as follows :-The motor and pumps being started, the by-pass valve or pump-suction-valves having been previously opened, the cage A with its load is raised by putting the lifting cylinders having the rams e e in connection with the delivery pipe 9 f the pumps, and the lowering cylinders having the ram 6 in connection with the suctionpipe g of the pumps through the controlling va ve G, the by-pass M being simultaneously closed. For lowering the cage and load, the communications are of a reverse character; the lowering cylinders being connected to the delivery, and the lifting cylinders to the suction, of the pumps.

To make up for leakage, thc'suction pipe 9* of the pumps is connected with a tank K by means of a pipe provided with a non-return valve 1).

For'actuating the valves G and M levers a a are provided respectively connected to each valve and operated by the hand-rope a passing through the cage.

The cage may, if preferred, be nearly counterbalanced by means of weights arranged independently of the hoisting cylinder.

What I claim as my invention and desire to secure by Letters Patent, is

In a lift system, the combination, with a suspended cage, a counterbalance for the same and approximately half the load, and raising and lowering cylinders furnished with rams, of a closed hydraulic circuit, a pump, an electrical motor for actuating the same, a main valve, a by-pass for short circuiting the pump, a valve therefor, and a lift-rope for operating said valves, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

JOHN WALTER BROWN.

Witnesses:

H. D. JAMEsoN, B. F. WILLIAMS. 

